Changing heat pump to heat strip

The problem with heat strips is they are very low power. Typically they are about 500 watts which is only enough to get the chill out of the air. The reason for this is usually the circuit serving the AC unit is a 15 AMP circuit. Using Ohm's law it is easy to calculate the amount of energy you can get out of a given circuit. A 120VAC 15 Amp circuit can at max support 1800 watts. This is the theoretical limit. This is limited by other things running on the same circuit as well as wire sizing etc. With a "heat strip" on an AC unit you would need a very undersized heat strip because you also have a blower running on the same circuit. This means you could have up to about 1000 watts of resistance heat available assuming the blower motor doesn’t take more than about 500 – 700 watts. While it is true that heat pumps become less efficient under 40 F the real difference is this. A resistance heater (heat strip) can produce about 3412 BTU where a heat pump can produce about 15,000 BTU. Because the heat pump starts at such a high BTU value for the amount of energy input it would need to be very cold before resistance heat would be superior. Final note heat pumps can stop working at or near freezing due to icing on the coils. That is expected and if detected can cause the compressor to shut down. This is usually an issue in high humidity situations. Bottom line I would never recommend a heat strip in lieu of a heat pump. A heat pump is always vastly superior in almost every situation. And even if you needed the heat it would be a rare situation where a heat strip would produce enough heat to keep a coach warm enough in less than 40F temperatures.